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i2c: add retry-process when slave NACK. [1/1]

Browse Source 
PD#SWPL-4761

Problem:
When slave device is busy processing, it is unable to handle the
incoming communication attempts. i2c master have to repeatedly attemp
communication  until the slave sends an ACK after receiving its slave
address.

Solution:
add retry-process when slave NACK.

Verify:
mesonaxg_s420_32_release

Change-Id: Ieb195176cac4b80e223ea6adb502ffd3bc9ef728
Signed-off-by: Daogao Xu <daogao.xu@amlogic.com>
This commit is contained in:
Daogao Xu
2019-02-28 15:01:10 +08:00
committed by Dongjin Kim
parent 90a6fefda0
commit 82e23fa9ae
1 changed files with 9 additions and 4 deletions
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13
drivers/amlogic/i2c/i2c-meson-master.c
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@@ -110,6 +110,7 @@ struct meson_i2c {
int count;
int pos;
int error;
int retries;
spinlock_t lock;
struct completion done;
@@ -324,6 +325,8 @@ static void meson_i2c_prepare_xfer(struct meson_i2c *i2c)
if (write)
meson_i2c_put_data(i2c, i2c->msg->buf + i2c->pos, i2c->count);
i2c->retries = 0;
}
static void meson_i2c_stop(struct meson_i2c *i2c)
@@ -346,7 +349,6 @@ static irqreturn_t meson_i2c_irq(int irqno, void *dev_id)
spin_lock(&i2c->lock);
meson_i2c_reset_tokens(i2c);
ctrl = readl(i2c->regs + REG_CTRL);
dev_dbg(i2c->dev, "irq: state %d, pos %d, count %d, ctrl %08x\n",
@@ -360,12 +362,15 @@ static irqreturn_t meson_i2c_irq(int irqno, void *dev_id)
* condition.
*/
dev_dbg(i2c->dev, "error bit set\n");
i2c->error = -ENXIO;
i2c->state = STATE_IDLE;
complete(&i2c->done);
if (++i2c->retries >= i2c->adap.retries) {
i2c->error = -ENXIO;
i2c->state = STATE_IDLE;
complete(&i2c->done);
}
goto out;
}
meson_i2c_reset_tokens(i2c);
switch (i2c->state) {
case STATE_READ:
if (i2c->count > 0) {